TE_IMPLICIT
if((yyvsp[(3) - (3)].type)->type == TTag && (yyvsp[(2) - (3)].constant) == TE_IMPLICIT) {
(yyval.constant) = TE_IMPLICIT;
if(oldtype->type == TTag && oldtype->tag.tagenv == TE_IMPLICIT) {
if($3->type == TTag && $2 == TE_IMPLICIT) {
$$ = TE_IMPLICIT;
if(oldtype->type == TTag && oldtype->tag.tagenv == TE_IMPLICIT) {
if(t->tag.tagenv == TE_IMPLICIT)